Compound jack



C. F. DAVEY COMPOUND JACK Ma'rch 21, 1939.

Filed March 29,` l1938 2 Sheets-Sheet l svi-IIIIIII I HHIIHIIIHII Il March 21, 1939. c, F. vDAVEY COMPOUND JACK 2 Sheets-Sheet 2 Filed March 29, 1938 'zcr: 7.

3mm V617 z j. 1era/'Z 17a IIIII llll lli)

Patente-d Mar. 2l, 1939 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to a compound jack of the type embodying a plurality of telescopic sections with screw means for advancing and retracting said sections relative to each other and an arrangement whereby movement of one of the sections will be compounded relative to the movement of another of the sections.

An object of the present invention is to provide a construction in a compound jack of the above character in which the telescopic sections are so arranged that the lowermost section will be innermost and the upper section will be outermost whereby when the several sections are disposed in their collapsed position the upper section will serve as a housing for its associated inner and lower sections.

Another object is to provide a compound jack embodying telescopic sections together' with an arrangement of worm gears meshing with screw threads on said sections in which the worm gears and the screw threads engaged thereby are maintained completely housed interiorly of the jack irrespective of the relative positions of the telescoped sections, so that the wearing surfaces of the gears and threads will be protected against dust and grit, and whereby the exterior of the jack may be readily kept free of lubricating oils or grease.

With the foregoing objects in View, together with such other objects and advantages as may subsequently appear, the invention is carried into effect as illustrated by way of example in the accompanying drawings, in which:

Fig. 1 is a View of the jack in elevation partly in section showing it in its collapsed position;

Fig. 2-is a View in horizontal section taken on the line 2-2 of Fig. 1;

Fig. 3 is a View in horizontal section taken on the line 3-3 of Fig. l; Y

Fig. 4 is a detail in horizontal section taken on the line 4--4 of Fig. 1;

Fig. 5 is a view in horizontal section taken on the line 5-5 of Fig. 1

' Fig. 6 is a view in section as seen on the line Fig. 7 is a view in vertical section, with parts in elevation, of the jack showing the telescopic sections thereof in a partly extended position relative to each other; Y

Fig. 8 is a detail in a horizontal section taken on the line 8 8 of Fig. 7;

Fig. 9 is a view in horizontal section taken on the lineA 9-9 of Fig. 7;

Fig. l0 is a view in elevation depicting a modilied form of the -invention in which the upper outer section of the jack is fitted with an adjust able engaging bracket;

Fig. 11 is a plan view of the structure shown in Fig. 10.

Referring to the drawings more specifically, A indicates generally the base of the jack which may be of any suitable construction but is here shown as embodying a housing having a top wall I4 and side wall I5. Erected on the base A is a tubular standard B having a base flange IG secured to the wall I4 by bolts Il. Extending vertically through the standard is a tubular shaft I8 the bore of which is rectangular in cross section. The upper end portion of the shaft I8 projects above the standard and is fitted with a worm wheel I9 and interposed between the worm wheel and the upper end of the standard is an end-thrust bearing 26. The lower end portion of the shaft I8 extends through the wall I4 into the interior of the base A and is fitted with a bevel gear 2| which meshes with a companion gear 22 on a drive shaft 23 which extends through a bearing 24 in one of the side walls I5 and is fitted with a attened end portion 25 for connection with a suitable driving means, such as a hand f crank or power driven shaft (not shown) Encircling the standard B is a vertically movable sleeveC having internal threads 26 engaged by the worm gear I9 and which sleeve C is splined to the standard B by keys 21 mounted on the inner lower end portion of the sleeve and which are slidably engaged with vertically extending channels or key-ways 28 extending longitudinally of the standard B.

Mounted in the rectangular bore of the shaft :1.

I8 is a shaft 29 of rectangular cross section which slidably fits the bore, and the upper end of which shaft projects above the upper end of the sleeve C and is fitted with a worm gear 30 having an external diameter exceeding that of the sleeve.

End thrust bearings 3| are interposed between the worm gear and the upper end of the sleeve C.

Encircling the sleeve C in telescopic relation thereto is an upper outer sleeve D formed with internal threads 32 which mesh with the worm gear 30. The sleeve D is splined on the sleeve C by keys 33 mounted on the upper end portion of the sleeve C which slidably engage key-ways 34 extending longitudinally of the sleeve D on the interior thereof. The upper end of the sleeve D is closed by a demountable end cap 35.

In assembling the jack the standard B is afxed to the base A by means of the bolts I1, whereupon the sleeve C is telescoped over the standard B by passing it downwardly over the upper end of the latter with the keys 21 in place on the sleeve C and engaged with the key-ways 28. The sleeve C is of a length greater than that of the standard B so that when disposed in its lowermost position relative to the latter the up-y per end portion of the sleeve C' will project a short distance above the upper end of the standard. The bearing assembly 2l) is then seated on the upper end of the standard B and the tubular shaft IB, preferably with the gear 2| ailixed to the lower end thereof, is put in place by passing the shaft upwardly through the lower end of the standard B.

The shaft I8 is of such length that when properly positioned in the standard B its upper end portion will project above the upper end of the standard B and above the bearing assembly 20 seated thereon. The worm gear I9 is then screwed into the upper end of the sleeve C to a seated position on the bearing 20; the gear being advanced over the upper end portion of the tubular shaft I8 and after being disposed in its operative seated position on the bearing 29 is afiixed to the shaft I8 as by a means of a key 36 as particularly shown in Fig. 4.

The outer sleeve D is then put in place by passing it downwardly over the upper end of the sleeve C with the keys 33 on the latter engaging the internal key-ways 34 on the sleeve D. When the sleeve D is disposed in its lowermost posititon re1- ative to the sleeve C the upper end portion thereof will project above the upper end of the sleeve C. The bearing assembly 3| is then put in place to seat on the upper end of the sleeve C' whereupon the worm gear 30 is screwed into place interlorly of the sleeve D, the upper end of which is then opened to receive the gear 30. The square shaft 29 is then passed downwardly through the gear 30 and disposed with its lower end extending into the rectangular bore of the tubular shaft I8 in slidable engagement with the latter. The gear 30 is then aiiixed to the shaft 29 by means of a set screw 31 as particularly shown in Fig. 2. The cap 35 is then put in place to cover the open upper end of the outer sleeve D. The shaft 23 with its associated beveled gear 32 is put in place at any convenient time to afford a driving connection with the gear 2 I.

It will be notedthat when the jack is assembled as above described the parts will be relatively disposed as shown in Fig. 1, that is with the standard B encompassed by the sleeve C and the latter encompassed by the sleeve D whereby the latter will afford a housing completely enclosing the inner telescoping sections of the jack thus protecting the wearing surfaces of the threads and worm gears against the deposit of dirt or grit thereon. This arrangement also provides a telescopic arrangement whereby the lowermost `section is outermost and overlying an intermediate section, which is advantageous in that the structure is rendered water shedding when exposed to the weather so that rain will not reach the interior surfaces of the jack. Furthermore, the screw threaded surfaces are completely concealed at all times irrespective of the relative positions of the telescopic sections so that oil or grease on such threads will not be exposed to the exterior of the jack thus enabling maintaining the outer surface of the jack free of such oil or grease and whereby the jack is rendered especially applicable for use where cleanliness is a desideratum.

In the application of the invention, the outer sleeve D may be attached in any suitable manner to the structure to be raised and lowered relative to the base A, and in some instances the upper end of the sleeve D may be arranged to abut against the underside of a structure to be raised and lowered.

However, the outer sleeve D may be equipped with an adjustable engaging member E as shown in Figs. 10 and 11, which embodies an annulus 38 slidably encircling the sleeve D and adapted to be engaged with the latter at various points throughout the length thereof as by means of teeth 39 formed on the sleeve D arranged in a row extending longitudinally of the latter and Vwhich teeth are adapted to be engaged by a tooth formed on the inner periphery of the ring 38. An engaging bracket 4I projects outwardly from the periphery of the ring 38 for effecting engagement with the structure to be raised and lowered by the jack. This arrangement admits of engagement by the jack of a structure extending close to and spaced slightly above the base A.

In the operation of the invention, assuming the parts of the jack to be disposed in the collapsed position shown in Fig. l, rotation of the tubular shaft I8 in a clock-wise direction will act through the worm I9 to effect upward movement of the sleeve C'by reason of the latter being held against rotation by the keys 21 engaging the key-ways 28 on the standard B so as to cause the internal threads 26 on the sleeve C to advance on the worm gear I9. On thus rotating the tubular shaft I8 the shaft 29 is revolved therewith thereby rotating the gear 30 so that the latter will effect elevation of the sleeve D relative to the sleeve C; the keys 33 on the sleeve C engaging the key-ways 3d on the sleeve C to hold the latter against rotation whereby the internal screw threads 32 on the sleeve D are advanced by the gear 3U. Upward movement of the sleeve C effects elevation of the worm gear 38 therewith and accordingly causes the square shaft 29 to move upwardly relative to the driven tubular shaft I8 which later rotates in the standard B. This elevation of the gear 30 of itself effects upward movementof the outer sleeve D, which `movement is accelerated by the lifting of the sleeve under the screw action of the gear r3II thereon, thus resulting in a compounded movement of the upper section of the jack.

Manifestly on having expanded the jack in effecting elevation of the sleeve D, reverse rotation of the shaft I8 will act to lower the sections C and D with the section D moving down at a speed exceeding the downward movement of the inner sleeve C.

While I have shown and described the jack as embodying a pair of telescoping sleeves C and D, it manifestly may be constructed with additional of such telescoping sleeves. To this end the square shaft 29 is tubular thereby adapting it to receive a smaller square shaft of a succeeding jack section when it is desired to increase the number of the sections from that here shown. It will be understood that in so increasing the jack sections the upper section will be arranged to overlie the adjacent section therebeneath.

Various other changes in the construction and arrangement of the parts may be employed as fall within the scope of the appended claims, and accordingly the invention embraces such changes.

I claim: Y

1. In a compound jack, Va standard, an inner sleeve slidably telescoping said standard, having internal screw threads, a tubular shaft extending longitudinally through said standard, a worm gear on said shaft meshing with the threads on said sleeve, a splined connection between said sleeve and standard, an outer sleeve encircling said inner sleeve having internal screw threads, a shaft engaged by said tubular shaft and slid able longitudinally therein, a worm gear on said last named shaft meshing with the threads on said outer sleeve, and a splined connection between said sleeves; said outer sleeve being arranged to encompass the inner sleeve, and the latter being arranged to encompass said standard.

2. In a jack, a tubular standard, a tubular shaft revolubly carried in said standard, a worm gear fixed on said shaft above said standard, an internally threaded inner sleeve encompassing said standard and meshing with said gear, a splined connection between said sleeve and standard including a key carried by said sleeve and a key-way on said standard engaged by said key, an internally threaded outer sleeve encompassing said inner sleeve, a splined connection between said sleeves, aworm gear meshing with the threads on said outer sleeve, and a shaft on which said last named gear is fixed extending into said tubular shaft in longitudinal slidable relation thereto and turnabletherewith.

3. In a jack, a tubular standard, a tubular shaft revolubly carried in said standard, a worm gear fixed on said shaft above said standard, an

internally threaded inner sleeve encompassing said standard and meshing with said gear, a splined connection between said sleeve and standard including a key carried by said sleeve and a key-way on said standard engaged by said key, an internally threaded outer sleeve encompassing said inner sleeve, a splined connection between said sleeves, including key-Ways formed interiorly of said outer sleeve and keys on said inner sleeve slidably engaging said key-ways, a worm gear meshing with the threads on said outer sleeve, and a shaft on which said last named gear is xed extending into said tubular shaft in longitudinal slidable relation thereto and turnable therewith.

4. In a compound jack, a standard, a plurality of internally threaded sleeves slidably encompassing said standard with adjacent sleeves telescoping each other progressively outward from said standard so that the lower ends of the outermost sleeve will overlie the adjacent inner sleeve, means for holding said Vsleeves against rotation relative to each other and to said standard, worm gears engaging the threads of each of said sleeves, and meansl for collectively rotating said worm gears to advance and retract said sleeves thereon.

CECIL F. DAVEY. 

